A conventional fan device for removing heat from a hear source such as a CPU in a computer is disclosed in FIG. 1 and generally includes blades on one side of the base and the fan device can only suck air from one side. Another fan device is disclosed in FIGS. 2 and 3, and includes blades on two sides of the base and the fan device may suck air from two sides so as to increase the efficiency for removing heat. Nevertheless, the air sucked from the two sides hit the base form which the blades extend such that noise and shaking become main concerns of the fan device. The base separates the air flows sucked form two sides and the speed, volume and pressure on the two sides of the fan device are different thereby generating turbulence at the outlet of the fan device. Besides, the blades are straight which is not benefit for the air flows.
The present invention intends to provide a fan device that includes at least one ring and a plurality of inner blades and outer plates extend from the inner periphery and the outer periphery of the at least one ring.